The Android 4.2.1 Jelly Bean has leaked for Samsung Galaxy S3 with build number I9300XXUFMB3. Most frequent firmware leaker Sammobile has exposed this test firmware but it seems that there are some new features has been added to it such as voice command, smart pause, smart scroll, lockscreen widgets and daydream. Some stuffs were not explored yet but this firmware looks interesting.

Advance users who may wants to try it out and may have a sneak preview of what’s new stuff Samsung has been added for the upcoming 4.2.1 Jelly Bean, you can simply manually install the Android 4.2.1 Jelly Bean stock ROM build I9300XXUFMB3. Just take note that this is not a final and an official released from Samsung and of course risks involved, flashing unofficial released may trip and increase the binary flash counter and certainly voids the device warranty. However, if you’re interested and wants to give it a shot, just grab the stock ROM on the source link below.

New Features and Enhancements in I9300XXUFMB3 4.2.1

Android 4.2.1 – JOP40D
Improved Ripple effect on Lockscreen
New Android 4.2.1 Lockscreen with widgets
Daydream (Settings>Display)
New Additions in Notification Center
Notifications are more actionable
Voice Command (Let’s you control various parts of the phone using voice commands)
Found more? Tell us about them in the comments below!

Quick Review of I9300XXUFMB3 4.2.1

1. The new directory system is there for internal sd. So all new data will be going to the “0” folder.
2. Also root explorer shows only 10gb of internal sd size.(as shown by root explorer, may be its reporting wrongly)
3. The system partition size is now reduced to 1.2gb.(as shown by root explorer, may be its reporting wrongly)
4. Rom is extremely smooth and responsive. Going to keep this for as long as i can.
5. The auto brightness bar in notification now has values to choose from -5 to +5

Here are the bugs I had encountered so far
1. Messaging FC (need to be wiped) 2. S planner FC if switched to week or month view, etc
3. Lockscreen option is gone (can’t add Lockscreen shortcuts now )
4. Owner’s information is not shown on Lockscreen
5. Notification panel setting is gone in Display option
6. Smart stay eye icon is persistent
7. The colors of clock, battery percentage and signal icon in the notification bar are mismatched.
thank’s to [Deadsol]

Disclaimer: Use of this guide is solely at your own risk. Stock ROM or firmware was not created by us. We shall not be held responsible any undesired outcomes may occur on your device.

WARNINGS:
This is repackaged firmware and will increase the device binary counter, if you don’t know what this means then don’t flash this firmware. This Firmware will also change your device status to Modified. This firmware doesn’t contain any Modem so the Modem you are using before flashing this firmware will remain. This is a PRE-RELEASE version so not official from KIES. As this is a PRE-RELEASE firmware so expect some minor bugs.

Odin flashing Procedures of 4.2.1 Jelly bean leaked

Download the I9300XXUFMB3 firmware: I9300XXUFMB3_I9300OJKFMB3_ILO.zip
Unzip the file. use winzip, winraror 7zip
Run Odin 3.04
Restart phone in download mode (Home+power+vol down)
Connect phone and wait until you get a yellow sign in Odin
Add I9300XXUFMB3_I9300OJKFMB3_HOME.tar.md5 to PDA
Make sure re-partition NOT ticked
Start flash, sit back and wait a few minutes.
If you encounter any issues with the firmware (Any FC, Bootloop etc)
Boot into recovery mode (Home+power+vol up)
Choose to wipe/factory reset. (THIS WILL ERASE ALL OF YOUR DATA INCLUDING YOUR INTERNAL SD CARD!)
Then choose reboot and you should be good to go!